Switch Extensions::TabHelper to use WebContents, WebContentsUserData.

chrome/browser/ui/gtk/tabs/dragged_view_gtk.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "chrome/browser/ui/gtk/tabs/dragged_view_gtk.h"
 
 #include <gdk/gdk.h>
 
 #include <algorithm>
 
@@ skipping 53 matching lines @@
       attached_tab_size_(TabRendererGtk::GetMinimumSelectedSize()),
       contents_size_(contents_size),
       close_animation_(this) {
   std::vector<WebContents*> data_sources(drag_data_->GetDraggedTabsContents());
   for (size_t i = 0; i < data_sources.size(); i++) {
     renderers_.push_back(new TabRendererGtk(GtkThemeService::GetFrom(
         Profile::FromBrowserContext(data_sources[i]->GetBrowserContext()))));
   }
 
   for (size_t i = 0; i < drag_data_->size(); i++) {
-    TabContents* tab_contents = TabContents::FromWebContents(
-        drag_data_->get(i)->contents_->web_contents());
+    WebContents* web_contents = drag_data_->get(i)->contents_->web_contents();
     renderers_[i]->UpdateData(
-        drag_data_->get(i)->contents_->web_contents(),
-        tab_contents->extension_tab_helper()->is_app(),
+        web_contents,
+        extensions::TabHelper::FromWebContents(web_contents)->is_app(),
         false); // loading_only
     renderers_[i]->set_is_active(
         static_cast<int>(i) == drag_data_->source_tab_index());
   }
 
   container_ = gtk_window_new(GTK_WINDOW_POPUP);
   SetContainerColorMap();
   gtk_widget_set_app_paintable(container_, TRUE);
   g_signal_connect(container_, "expose-event", G_CALLBACK(OnExposeThunk), this);
   gtk_widget_add_events(container_, GDK_STRUCTURE_MASK);
@@ skipping 377 matching lines @@
     if (!attached_) {
       paint_at = widget_width / kScalingFactor -
           GetWidthInTabStripFromTo(0, index + 1);
     }
   }
 
   cairo_set_source_surface(cr, surface, paint_at, 0);
   cairo_paint(cr);
   cairo_surface_destroy(surface);
 }